Local artist brought in a Roland Cube 60 that has been around. He said there was a problem with the reverb channel, which I later confirmed is what I encountered below.
I powered it up cold, no instrument plugged in, and turned up the reverb knob and in seconds was random popping/gunshots. It was controllable with reverb control. I turned down the (preamp) volume and the noise continued. When I disconnected the reverb tank output, the noise stopped. Same with disconnect RT input. So it looks like it is coming from the SIP chip amplifier circuit that drives the reverb tank. The problem is, the noise stopped and only occurrs now very sporadically...before I could put a scope on anything. I left it off over the weekend, and today powered it up and it is quiet with a few random pops. I probed, poked, tapped, and nothing will provoke it. I dont have any spray coolant so that will be my next step.
My thought is, this must be an instance of a generally occurring type of problem with a twenty or thirty something solid state amplifier, whether it be voltage source or signal path issue... Any thoughts or comments would be appreciated. Thanks.
I powered it up cold, no instrument plugged in, and turned up the reverb knob and in seconds was random popping/gunshots. It was controllable with reverb control. I turned down the (preamp) volume and the noise continued. When I disconnected the reverb tank output, the noise stopped. Same with disconnect RT input. So it looks like it is coming from the SIP chip amplifier circuit that drives the reverb tank. The problem is, the noise stopped and only occurrs now very sporadically...before I could put a scope on anything. I left it off over the weekend, and today powered it up and it is quiet with a few random pops. I probed, poked, tapped, and nothing will provoke it. I dont have any spray coolant so that will be my next step.
My thought is, this must be an instance of a generally occurring type of problem with a twenty or thirty something solid state amplifier, whether it be voltage source or signal path issue... Any thoughts or comments would be appreciated. Thanks.
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